Most valuable character

most-valuable-character/index.js

@@ -0,0 +1,11 @@
+// https://www.codewars.com/kata/most-valuable-character/javascript
+
+function solve(st) {
+  return [...new Set([...st])].map(c => {
+    return [c, st.lastIndexOf(c) - st.indexOf(c)];
+  }).sort((a, b) => {
+    const c = b[1] - a[1];
+    if (c === 0) return a[0].localeCompare(b[0]);
+    return c;
+  })[0][0];
+}